The present invention is directed to a process for producing an optical fiber of a high tensile strength, said process includes pulling a fiber from a glass substance, surrounding the fiber and glass substance in a dry gas atmosphere containing a drying agent which reacts with moisture.
In U.S. patent application Ser. No. 122,448, filed Nov. 19, 1987, which claims priority from German Patent Application P 37 01 977.5, and whose disclosure is incorporated by reference, fibers with high tensile strength of around 600 MPa were obtained by drawing the fiber from a glass mass while in an atmosphere containing a drying agent composed of thionyl chloride, which is a chlorine-containing drying agent.